1. Field of the Invention
The invention relates generally to a condenser housing for microscopes with an annular slit to receive filter slides and, more particularly, to such housings having guide rails and a stationary stop, the filter slides being immobilized by means of an arresting mechanism in at least one defined position within the guide rails.
2. Description of the Prior Art
Condenser housings of the configuration described above are known in principle. The filter slides have, on one longitudinal side, two indexing notches which are spaced at a selected distance from one another and are engaged successively during the insertion and extraction of the filter slides by a movable locking roller biased by a spring. The slides are not secured adequately in a stand-by position after extraction by the locking mechanism because the last index position is frequently accidently passed over. Furthermore, the filter slides may often be inserted incorrectly, i.e., with their top side downward into the condenser housing. In such a case, locking is impossible.